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Bringing Science Solutions to the WorldThu, 30 Jul 2015 19:56:46 +0000en-UShourly1http://wordpress.org/?v=4.2.2Meet the High-Performance Single-Molecule Diodehttp://newscenter.lbl.gov/2015/07/29/high-performance-single-molecule-diode/
http://newscenter.lbl.gov/2015/07/29/high-performance-single-molecule-diode/#respondWed, 29 Jul 2015 18:09:34 +0000https://newscenter.lbl.gov/?p=33900Researchers from Columbia University and Berkeley Lab have created the world’s highest-performance single-molecule diode. Development of a functional single-molecule diode is a major pursuit of the electronics industry.

Researchers from Berkeley Lab and Columbia University have created the world’s highest-performance single-molecule diode using a combination of gold electrodes and an ionic solution. (Image courtesy of Latha Venkataraman, Columbia University)

A team of researchers from Columbia University and Berkeley Lab’s Molecular Foundry has passed a major milestone in molecular electronics with the creation of a single-molecule diode that outperforms the best of its predecessors by a factor of 50.

“Using an ionic solution, two gold electrodes of dramatically different exposed surface areas, and a single symmetric molecule specially designed by the Luis Campos’ group at Columbia, we were able to create a diode that resulted in a rectification ratio, the ratio of forward to reverse current at fixed voltage, in excess of 200, a record for single-molecule devices,” says Latha Venkataraman, Associate Professor of Applied Physics at Columbia University.

“The asymmetry necessary for diode behavior originates with the different exposed electrode areas and the ionic solution,” says Jeff Neaton, Director of the Molecular Foundry, a U.S. Department of Energy (DOE) Office of Science User Facility. “This leads to different electrostatic environments surrounding the two electrodes and superlative single-molecule device behavior.”

Venkataraman, Campos and Neaton are the corresponding authors of a paper describing this research in Nature Nanotechnology. The paper is titled “Single-molecule diodes with high rectification ratios through environmental control.” The lead author is Brian Capozzi, a member of Venkataraman’s group who discovered the environmental asymmetric technique. Other co-authors are Jianlong Xia, Olgun Adak, Emma Dell, Zhen-Fei Liu and Jeffrey Taylor

With “smaller and faster” as the driving mantra of the electronics industry, single-molecule devices represent the ultimate limit in electronic miniaturization. In 1974, molecular electronics pioneers Mark Ratner and Arieh Aviram theorized that an asymmetric molecule could act as a rectifier, a one-way conductor of electric current. Since then, development of functional single-molecule electronic devices has been a major pursuit with diodes – one of the most widely used electronic components – being at the top of the list.

Schematic of the molecular junction created using asymmetric area electrodes which functions as a diode, allowing current to flow in one direction only.

A typical diode consists of a silicon p-n junction between a pair of electrodes (anode and cathode) that serves as the “valve” of an electrical circuit, directing the flow of current by allowing it to pass through in only one “forward” direction. The asymmetry of a p-n junction presents the electrons with an “on/off” transport environment. Scientists have previously fashioned single-molecule diodes either through the chemical synthesis of special asymmetric molecules that are analogous to a p-n junction; or through the use of symmetric molecules with different metals as the two electrodes. However, the resulting asymmetric junctions yielded low rectification ratios, and low forward current. The Columbia University groups, working together with Neaton and his group, have discovered a way to address both deficiencies.

Venkataraman and Campos and their respective research groups fabricated a high-performing rectifier from junctions made of symmetric oxidized thiophene derivatives with molecular resonance in nearly perfect alignment with the Fermi electron energy levels of the gold electrodes. Symmetry was broken by a substantial difference in the size of the area on each gold electrode that was exposed to the ionic solution. Owing to the asymmetric electrode area, the ionic solution, and the junction energy level alignment, a positive voltage increases current substantially; a negative voltage suppresses it equally significantly.

“Electron flow at molecular length-scales is dominated by quantum tunneling,” Neaton explains. “The efficiency of the tunneling process depends intimately on the degree of alignment of the molecule’s discrete energy levels with the electrode’s continuous spectrum. In a molecular rectifier, this alignment is enhanced for positive voltage, leading to an increase in tunneling, and is reduced for negative voltage. At the Molecular Foundry we developed an approach to accurately compute energy-level alignment and tunneling probability in single-molecule junctions to evaluate the hypothesis by the Columbia team. This method allowed myself and Zhenfei Liu to understand the diode behavior.”

“The ionic solution, combined with the asymmetry in electrode areas, allows us to control the junction’s electrostatic environment simply by changing the bias polarity,” Neaton says. “In addition to breaking symmetry, double layers formed by ionic solution also generate dipole differences at the two electrodes, which is the underlying reason behind the asymmetric shift of molecular resonance. The Columbia group’s experiments showed that with the same molecule and electrode setup, a non-ionic solution yields no rectification at all.”

The Columbia University and Berkeley Lab team believes their new approach to a single-molecule diode provides a general route for tuning nonlinear nanoscale-device phenomena that could be applied to systems beyond single-molecule junctions and two-terminal devices.

“We expect the understanding gained from this work to be applicable to ionic liquid gating in other contexts, and mechanisms to be generalized to devices fabricated from two-dimensional materials,” says Capozzi. “Beyond devices, these tiny molecular circuits are petri dishes for revealing and designing new routes to charge and energy flow at the nanoscale. What is exciting to me about this field is its multidisciplinary nature – the need for both physics and chemistry – and the strong beneficial coupling between experiment and theory.

Adds Neaton, “With the increasing level of experimental control at the single-molecule level, and improvements in theoretical understanding and computational speed and accuracy, we’re just at the tip of the iceberg with what we can understand and control at these small length scales.”

This research was primarily supported National Science Foundation. The computational work was supported by the DOE Office of Science and performed at National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility also hosted at Berkeley Lab.

A news release from Columbia University that first reported this research can be viewed here

# # #

Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit the Office of Science website at science.energy.gov/.

The term “plasmons” might sound like something from the soon-to-be-released new Star Wars movie, but the effects of plasmons have been known about for centuries. Plasmons are collective oscillations of conduction electrons (those loosely attached to molecules and atoms) that roll across the surfaces of metals while interacting with photons. For example, plasmons from nanoparticles of gold, silver and other metals interact with visible light photons to generate the vibrant colors displayed by stained glass, a technology that dates back more than 1,000 years. But plasmons have high-technology applications as well. In fact, there’s even an emerging technology named for them – plasmonics – that holds great promise for superfast computers and optical microscopy.

At the heart of the high-technology applications of plasmons is their unique ability to confine the energy of a photon into a spatial dimension smaller than the photon’s wavelength. Now, a team of researchers with Berkeley Lab’s Materials Sciences Division, working at the Advanced Light Source (ALS), has generated and detected plasmons that boast one of the strongest confinement factors ever: the plasmon wavelength is only one hundredth of the free-space photon wavelength.

By focusing infrared light onto the tip of an Atomic Force Microscope, the researchers were able to observe what are called “Luttinger-liquid” plasmons in metallic single-walled nanotubes. A Luttinger-liquid is the theory that describes the flow of electrons through one-dimensional objects, such as a single-walled nanotube (SWNT), much as the Fermi-liquid theory describes the flow of electrons through most two- and three-dimensional metals.

“It is amazing that a plasmon in an individual nanotube, a 1-D object barely a single nanometer in diameter, can even be observed at all,” says Feng Wang, a condensed matter physicist with Berkeley Lab’s Materials Sciences Division who led this work. “Our use of scattering-type scanning near-field optical microscopy (s-SNOM) is enabling us to study Luttinger-liquid physics and explore novel plasmonic devices with extraordinary sub-wavelength confinement, almost 100 million times smaller in volume than that of free-space photons. What we’re observing could hold great promise for novel plasmonic and nanophotonic devices over a broad frequency range, including telecom wavelengths.”

Wang, who also holds appointments with the University California (UC) Berkeley Physics Department and the Kavli Energy NanoScience Institute (Kavli-ENSI), is the corresponding author of a paper in Nature Photonics that describes this research. The paper is titled “Observation of a Luttinger-liquid plasmon in metallic single-walled carbon nanotubes.” The co-lead authors are Zhiwen Shi and Xiaoping Hong, both members of Wang’s UC Berkeley research group. Other co-authors are Hans Bechtel, Bo Zeng, Michael Martin, Kenji Watanabe, Takashi Taniguchi and Yuen-Ron Shen.

From left, Hans Bechtel, Zhiwen Shi, Michael Martin and Feng Wang were part of a research team that used the Adcvanced Light Source’s Beamline 5.4.1 to observed Luttinger-liquid plasmons in metallic SWNTs. (Photo by Roy Kaltschmidt)

Despite the enormous potential of plasmons for the integration of nanoscale photonics and electronics, the development of nanophotonic circuits based on classical plasmons has been significantly hampered by the difficulty in achieving broadband plasmonic waveguides that simultaneously exhibit strong spatial confinement, a high quality factor and low dispersion. The observations of Wang and his colleagues demonstrate that Luttinger-liquid plasmon of 1-D conduction electrons in SWNTs behaves much differently from classical plasmons.

“Luttinger-liquid plasmons in SWNTs propagate at semi-quantized velocities that are independent of carrier concentration or excitation wavelength, and simultaneously exhibit extraordinary spatial confinement, a high quality factor and low dispersion,” says co-lead author Shi. “Usually, to be manipulated efficiently with a photonic device, the light wavelength is required to be smaller than the device. By concentrating photon energy at deep sub-wavelength scales, Luttinger-liquid plasmons in SWNTs effectively reduce the light wavelength. This should allow for the miniaturization of photonic devices down to the nanometer scale.”

Wang, Shi, Hong and their colleagues observed Luttinger-liquid plasmons using the s-SNOM setup at ALS Beamline 5.4.1. Metallic SWNTs with diameters ranging from 1.2 to 1.7 nanometers were grown, purified and then deposited on a boron nitride substrate. Single wavelength infrared light was focused onto the tip of an Atomic Force Microscope to excite and detect a plasmon wave along an SWNT.

“Our direct observation of Luttinger-liquid plasmons opens up exciting new opportunities,” Wang says. “For example, we’re now exploring these plasmons in telecom wavelengths, the most widely used in photonics and integrated optics. We’re also learning how the properties of these plasmons might be manipulated through electrostatic gating, mechanical strain and external magnetic fields.”

This research was primarily supported by the U.S. Department of Energy’s Office of Science.

]]>http://newscenter.lbl.gov/2015/07/28/shortest-wavelength-plasmons-ever/feed/0Unlocking the Rice Immune Systemhttp://newscenter.lbl.gov/2015/07/24/unlocking-the-rice-immune-system/
http://newscenter.lbl.gov/2015/07/24/unlocking-the-rice-immune-system/#respondFri, 24 Jul 2015 18:01:51 +0000https://newscenter.lbl.gov/?p=33888JBEI, UC Davis and Berkeley Lab researchers have identified a bacterial signaling molecule that triggers an immunity response in rice plants, enabling the plants to resist a devastating blight disease. Rice is not only a staple food, it is the model for grass-type advanced biofuels.

Rice is a staple for half the world’s population and the model plant for grass-type biofuel feedstocks (Photo courtesy of IRRI)

A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team of researchers led by scientists with the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI) and the University of California (UC) Davis.

The research team discovered that a tyrosine-sulfated bacterial protein called “RaxX,” activates the rice immune receptor protein called “XA21.” This activation triggers an immune response against Xanthomonas oryzaepv.oryzae (Xoo), a pathogen that causes bacterial blight, a serious disease of rice crops.

“Our results show that RaxX, a small, previously undescribed bacterial protein, is required for activation of XA21-mediated immunity to Xoo,” says Pamela Ronald, a plant geneticist for both JBEI and UC Davis who led this study. “XA21 can detect RaxX and quickly mobilize its defenses to mount a potent immune response against Xoo. Rice plants that do not carry the XA21 immune receptor or other related immune receptors are virtually defenseless against bacterial blight.”

Ronald, who directs JBEI’s grass genetics program and is a professor in the UC Davis Department of Plant Pathology, is one of two corresponding authors of a paper describing this research in Science Advances, along with Benjamin Schwessinger, a grass geneticist with JBEI’s Feedstocks Division at the time of this study and now with the Australian National University. The paper is titled “The rice immune receptor XA21 recognizes a tyrosine-sulfated protein from a Gram-negative bacterium.” (See end of story for a complete list of authors.)

Pamela Ronald is a leading authority on plant genetics who holds joint appointments with the Joint BioEnergy Institute and the University of California at Davis. (Photo by John Stumbos, UC Davis)

Rice is a staple food for half the world’s population and a model plant for perennial grasses, such as Miscanthus and switchgrass, which are prime feedstock candidates for the production of clean, green and renewable cellulosic biofuels. Just as bacterial blight poses a major threat to rice crops, bacterial infections of grass-type fuel plants could present major problems for the future production of advanced biofuels. However, the mechanisms by which bacteria infect such grasses is poorly understood.

“Pathogens of grass-type biofuel crops that would reduce the yield of fuel-producing biomass likely use similar infection mechanisms to Xoo,” says Schwessinger. “Having identified the activator of XA21, we will be able to study the rice immune system in far greater detail than ever before. As rice is the model for grass-type biofuel feedstocks, this might help in the future engineering of more disease-resistant grass-type biofuel crops.”

Most plants and many animals can only defend themselves against a given disease if they carry specialized immune receptors that sense the invading pathogen behind the disease. In 2009, Ronald and her group identified a small bacterial protein they named “Ax21” as the molecular key that binds to the XA21 receptor to activate a rice plant’s immune response. Diligent follow-up research by her group led to Ronald retracting these results and continuing the search for the true key.

“We were ecstatic with our results in 2009 because identifying the molecule that XA21 recognizes provides an important piece to the puzzle of how the rice plant is able to respond to infection,” Ronald says, “but then it was back to the drawing board. Now we have the real XA21 activator.”

Benjamin Schwessinger and Rory Pruitt were co-lead authors of a Science Advances paper that described the identification of a bacterial signaling molecule which triggers immunity response in rice. (Photo by Daniel Caddell)

To uncover the true XA21 activator, Ronald and her collaborators studied mutations around an operon known as “RaxSTAB.” Operons are small groups of genes with related functions that are co-transcribed in a single strand of messenger RNA.

“We hypothesized that the activator of XA21 might be encoded in the proximity of the molecular machinery that we already knew was involved in production of the activator,” says Rory Pruitt, a member of Ronald’s research group and a co-lead author with Schwessinger of the Science Advances paper. “One of these bacterial mutants had a deletion of a then unknown gene, now called raxX.”

Adds Schwessinger, “When we looked more closely in this operon region we identified raxX as a potentially expressed gene. This small gene stuck out as it was very well conserved in other Xanthomonas that encode RaxSTAB but not conserved in any other bacteria that miss this operon.”

In addition to its implications for future grass-type biofuel feedstocks, the revelation of RaxX as the bacterial molecule that triggers the XA21-mediated immune response also holds important implications for the worldwide supply of rice. The research team has shown that a number of strains of the blight bacteria can evade XA21-mediated immunity because they encode a variant of raxX alleles.

“Like prescribing the best vaccination for the flu each season by monitoring which flu strains are going to be the most prevalent, it should be possible to screen wild Xoo populations in the rice-growing regions of Asia and Africa for whether they encode RaxX alleles that are recognized by XA21,” says Schwessinger. “We can then inform farmers which rice varieties will be resistant to those bacterial populations.”

Schwessinger also notes that several major human diseases involve tyrosine-sulfated proteins, including HIV. However the precise role of tyrosine sulfation in receptor binding and cell invasion is not understood.

“Understanding the RaxX/XA21 ligand-receptor pair might help medical researchers better understand the role of tyrosine sulfation for receptor binding in human disease,” Schwessinger says. “This could lead to the development of novel components that block the binding of specific tyrosine-sulfated proteins.”

This research was supported by both the DOE Office of Science, the National Institutes of Health, and the Human Frontier Science Program.

Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit the Office of Science website at science.energy.gov/.

]]>http://newscenter.lbl.gov/2015/07/24/unlocking-the-rice-immune-system/feed/0A Most Singular Nano-Imaging Techniquehttp://newscenter.lbl.gov/2015/07/16/single/
http://newscenter.lbl.gov/2015/07/16/single/#respondThu, 16 Jul 2015 18:03:46 +0000https://newscenter.lbl.gov/?p=33831“SINGLE” is a new imaging technique that provides the first atomic-scale 3D structures of individual nanoparticles in solution. This is an important step for improving the design of colloidal nanoparticles for catalysis and energy research applications.

SINGLE uses in situ TEM imaging of platinum nanocrystals freely rotating in a graphene liquid cell to determine the 3D structures of individual colloidal nanoparticles.

Just as proteins are one of the basic building blocks of biology, nanoparticles can serve as the basic building blocks for next generation materials. In keeping with this parallel between biology and nanotechnology, a proven technique for determining the three dimensional structures of individual proteins has been adapted to determine the 3D structures of individual nanoparticles in solution.

A multi-institutional team of researchers led by the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab), has developed a new technique called “SINGLE” that provides the first atomic-scale images of colloidal nanoparticles. SINGLE, which stands for 3D Structure Identification of Nanoparticles by Graphene Liquid Cell Electron Microscopy, has been used to separately reconstruct the 3D structures of two individual platinum nanoparticles in solution.

“Understanding structural details of colloidal nanoparticles is required to bridge our knowledge about their synthesis, growth mechanisms, and physical properties to facilitate their application to renewable energy, catalysis and a great many other fields,” says Berkeley Lab director and renowned nanoscience authority Paul Alivisatos, who led this research. “Whereas most structural studies of colloidal nanoparticles are performed in a vacuum after crystal growth is complete, our SINGLE method allows us to determine their 3D structure in a solution, an important step to improving the design of nanoparticles for catalysis and energy research applications.”

Alivisatos, who also holds the Samsung Distinguished Chair in Nanoscience and Nanotechnology at the University of California Berkeley, and directs the Kavli Energy NanoScience Institute at Berkeley (Kavli ENSI), is the corresponding author of a paper detailing this research in the journal Science. The paper is titled “3D Structure of Individual Nanocrystals in Solution by Electron Microscopy.” The lead co-authors are Jungwon Park of Harvard University, Hans Elmlund of Australia’s Monash University, and Peter Ercius of Berkeley Lab. Other co-authors are Jong Min Yuk, David Limmer, Qian Chen, Kwanpyo Kim, Sang Hoon Han, David Weitz and Alex Zettl.

Colloidal nanoparticles are clusters of hundreds to thousands of atoms suspended in a solution whose collective chemical and physical properties are determined by the size and shape of the individual nanoparticles. Imaging techniques that are routinely used to analyze the 3D structure of individual crystals in a material can’t be applied to suspended nanomaterials because individual particles in a solution are not static. The functionality of proteins are also determined by their size and shape, and scientists who wanted to image 3D protein structures faced a similar problem. The protein imaging problem was solved by a technique called “single-particle cryo-electron microscopy,” in which tens of thousands of 2D transmission electron microscope (TEM) images of identical copies of an individual protein or protein complex frozen in random orientations are recorded then computationally combined into high-resolution 3D reconstructions. Alivisatos and his colleagues utilized this concept to create their SINGLE technique.

“In materials science, we cannot assume the nanoparticles in a solution are all identical so we needed to develop a hybrid approach for reconstructing the 3D structures of individual nanoparticles,” says co-lead author of the Science paper Peter Ercius, a staff scientist with the National Center for Electron Microscopy (NCEM) at the Molecular Foundry, a DOE Office of Science User Facility.

Peter Ercius with the TEAM I electron microscope at the Molecular Foundry’s National Center for Electron Microscopy (NCEM). (Photo by Roy Kaltschmidt)

“SINGLE represents a combination of three technological advancements from TEM imaging in biological and materials science,” Ercius says. “These three advancements are the development of a graphene liquid cell that allows TEM imaging of nanoparticles rotating freely in solution, direct electron detectors that can produce movies with millisecond frame-to-frame time resolution of the rotating nanocrystals, and a theory for ab initio single particle 3D reconstruction.”

The graphene liquid cell (GLC) that helped make this study possible was also developed at Berkeley Lab under the leadership of Alivisatos and co-author Zettl, a physicist who also holds joint appointments with Berkeley Lab, UC Berkeley and Kavli ENSI. TEM imaging uses a beam of electrons rather than light for illumination and magnification but can only be used in a high vacuum because molecules in the air disrupt the electron beam. Since liquids evaporate in high vacuum, samples in solutions must be hermetically sealed in special solid containers – called cells – with a very thin viewing window before being imaged with TEM. In the past, liquid cells featured silicon-based viewing windows whose thickness limited resolution and perturbed the natural state of the sample materials. The GLC developed at Berkeley lab features a viewing window made from a graphene sheet that is only a single atom thick.

“The GLC provides us with an ultra-thin covering of our nanoparticles while maintaining liquid conditions in the TEM vacuum,” Ercius says. “Since the graphene surface of the GLC is inert, it does not adsorb or otherwise perturb the natural state of our nanoparticles.”

The Berkeley Lab GLC improves the resolution of TEM imaging with a viewing window made from a graphene sheet that is only a single atom thick.

Working at NCEM’s TEAM I, the world’s most powerful electron microscope, Ercius, Alivisatos and their colleagues were able to image in situ the translational and rotational motions of individual nanoparticles of platinum that were less than two nanometers in diameter. Platinum nanoparticles were chosen because of their high electron scattering strength and because their detailed atomic structure is important for catalysis.

“Our earlier GLC studies of platinum nanocrystals showed that they grow by aggregation, resulting in complex structures that are not possible to determine by any previously developed method,” Ercius says. “Since SINGLE derives its 3D structures from images of individual nanoparticles rotating freely in solution, it enables the analysis of heterogeneous populations of potentially unordered nanoparticles that are synthesized in solution, thereby providing a means to understand the structure and stability of defects at the nanoscale.”

The next step for SINGLE is to recover a full 3D atomic resolution density map of colloidal nanoparticles using a more advanced camera installed on TEAM I that can provide 400 frames-per-second and better image quality.

“We plan to image defects in nanoparticles made from different materials, core shell particles, and also alloys made of two different atomic species,” Ercius says.

A movie of a single rotating Pt nanocrystal showing 2D projected TEM still snapshots in many orientations for ab initio particle reconstruction can be viewed here

# # #

Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit the Office of Science website at science.energy.gov/.

The Open Cut is an inactive mine pit that draws more than 40,000 visitors to Lead, SD every year. Credit: Kate Greene, Berkeley Lab

The town of Lead, South Dakota was once famous for its prodigious gold and silver stores, but lately it’s been getting attention for its particle physics experiments instead.

Scientists hope these experiments, housed in the Sanford Underground Research Facility (Sanford Lab) in the former Homestake Mine, will uncover truths about the nature of the universe from dark matter to neutrinos. On June 30, the Sanford Lab Homestake Visitor Center, a facility that highlights the mine’s gold and silver past and the lab’s particle physics future, held its grand opening ceremony.

Engineers, scientists, and students from the U.S. Department of Energy’s Lawrence Berkeley National Lab (Berkeley Lab) have been major drivers and key players in the creation and management of Sanford Lab, in collaboration with the State of South Dakota and dozens of research universities.

Additionally, Berkeley Lab manages projects and facilities nearly a mile underground, including the forthcoming LUX-ZEPLIN (LZ) project, a next-generation dark-matter experiment, and the Berkeley Low Background Facility. Berkeley Lab is also a collaborating member in the current LUX dark matter experiment and the Majorana Demonstrator neutrino project, also located deep within the former gold mine.

The new 8,000-square- foot visitor center overlooks the Open Cut, an enormous mining pit created in the early days of Homestake. The visitor center features a classroom, a gift shop, and a 3,000 square-foot exhibition space that details the mine’s history and current and future research at Sanford Lab. Berkeley Lab Public Affairs contributed content to visitor center exhibits.

The ribbon-cutting event featured speakers from the South Dakota Science and Technology Authority, the mayor of Lead, and Dennis Daugaard, the governor of South Dakota. Former governor and current South Dakota Senator Mike Rounds was also in attendance.

Murdock “Gil” Gilchriese, LZ project scientist and physicist in Berkeley Lab’s Physics Division attended the event. He was impressed, he said, by the new facility, the exhibits, and the general excitement about the research. “The combination of history and the future science—that’s what this is about—is fantastic,” Gilchriese said.

The Sanford Lab Homestake Visitor Center was funded in part by T. Denny Sanford, who donated $70 million to build the underground lab and the State of South Dakota, which provided $40 million in funds for the lab.

]]>http://newscenter.lbl.gov/2015/07/14/new-visitor-center-in-south-dakota-highlights-underground-science/feed/0Gut Microbes Enable Coffee Pest to Withstand Extremely Toxic Concentrations of Caffeinehttp://newscenter.lbl.gov/2015/07/14/microbes-coffee-pest/
http://newscenter.lbl.gov/2015/07/14/microbes-coffee-pest/#respondTue, 14 Jul 2015 15:04:06 +0000https://newscenter.lbl.gov/?p=33784Scientists discovered that coffee berry borers worldwide share 14 bacterial species in their digestive tracts that degrade and detoxify caffeine. They also found the most prevalent of these bacteria has a gene that helps break down caffeine. Their research sheds light on the ecology of the destructive bug and could lead to new ways to fight it.

Berkeley Lab’s Javier Ceja-Navarro discusses how researchers are learning how to utilize microbes that live inside the digestive tracts of insects for pest control, improved agriculture, and biofuel production.

The coffee berry borer is the most devastating coffee pest in the world. The tiny beetle is found in most regions where coffee is cultivated, and a big outbreak can slash crop yield by 80 percent.

It’s also a caffeine fiend. The insect is the only coffee pest that uses the caffeine-rich bean as its sole source of food and shelter. It bores into the bean and spends most of its life tucked inside, where it’s exposed to what should be an extremely toxic amount of caffeine for its mass: the equivalent of a 150-pound person downing 500 shots of espresso. Caffeine is harmful to most insects and is believed to act as a natural pest repellant. So how does the coffee berry borer thrive in such a hostile environment?

It relies on the bacteria in its gut, according to new research by scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), the U.S. Department of Agriculture (USDA), and Mexico’s El Colegio de la Frontera Sur (ECOSUR). Their study appears July 14 in the journal Nature Communications.

The scientists discovered that coffee berry borers worldwide share 14 bacterial species in their digestive tracts that degrade and detoxify caffeine. They also found the most prevalent of these bacteria has a gene that helps break down caffeine. Their research sheds light on the ecology of the destructive bug and could lead to new ways to fight it.

“Instead of using pesticides, perhaps we could target the coffee berry borer’s gut microbiota. We could develop a way to disrupt the bacteria and make caffeine as toxic to this pest as it is to other insects,” says Javier Ceja-Navarro, a scientist in Berkeley Lab’s Earth Sciences Division and lead author of the paper.

Ceja-Navarro and Eoin Brodie of Berkeley Lab led the effort with the USDA’s Fernando Vega, an expert on the coffee berry borer and one of the study’s corresponding authors. Zhao Hao, Ulas Karaoz, Trent Northen, Stefan Jenkins, and Hsiao Chien-Lim of Berkeley Lab; Francisco Infante of ECOSUR; and Petr Kosina of Mexico’s International Maize and Wheat Improvement Center also contributed.

Scientists have extensively studied the beetle, but very little research has focused on how it subsists solely on coffee berries, and the Berkeley Lab and USDA-led team is the first to explore the role of the bacteria in its gut. The idea isn’t as far-fetched as it may seem. Microbes perform key functions in all ecosystems, from cycling nutrients in the soil to shaping the human immune system from inside our digestive tract.

“Before this research, I worked with atomic force microscopy, where you have to keep your hands steady, so I got good at it,” says Ceja-Navarro. “But I had to cut down on coffee!”

The scientists immersed the gut bacteria in a special medium containing caffeine as the main nutrient, so only the bacteria that degrade caffeine survived. Fourteen bacterial species were isolated, most of which were found in beetles from all seven coffee-producing regions and the laboratory colony. These bacteria appear to subsist on caffeine as their sole source of carbon and nitrogen. One of the bacteria, Pseudomonas fulva, was the most prevalent, according to their DNA-based geographic survey.

The scientists also screened the bacteria for a gene called ndmA that is known to transform caffeine. They found that only P. fulva possessed this gene. Ceja-Navarro surmises the other bacteria help break down caffeine using different genes.

To confirm the role of P. fulva in the degradation of caffeine, the researchers administered an antibiotic to a group of beetles that wiped out their gut microbiota. They then fed these beetles a standardized diet based on coffee beans and then analyzed their feces. The caffeine passed through their digestive tracts intact without a hint of degradation.

The scientists next added P. fulva to the beetles’ diet to restock their guts with the caffeine-degrading bacterium. The feces from these beetles were devoid of caffeine, indicating the detoxification process had been restored.

“After that, we knew gut bacteria were key to the beetle’s survival strategy and its ecology in general,” says Eoin Brodie, the study’s senior author. “This is a clear example of how microorganisms, with their rapid adaptive capabilities, can enable higher organisms to colonize new environments.”

The research was funded by the U.S. Department of Agriculture, the Laboratory Directed Research and Development program at Berkeley Lab, and Mexico’s National Council for Science and Technology.

###

Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

Additional information:

The paper “Gut microbiota mediate caffeine detoxification in the primary insect pest of coffee” was published in Nature Communications’ onJuly 14, 2015.

]]>http://newscenter.lbl.gov/2015/07/14/microbes-coffee-pest/feed/0Bay Area National Laboratories Jointly Launch New Small Business Voucher Pilot for Emerging Cleantech Companieshttp://newscenter.lbl.gov/2015/07/09/bay-area-national-laboratories-jointly-launch-new-small-business-voucher-pilot-for-emerging-cleantech-companies/
http://newscenter.lbl.gov/2015/07/09/bay-area-national-laboratories-jointly-launch-new-small-business-voucher-pilot-for-emerging-cleantech-companies/#respondThu, 09 Jul 2015 16:51:53 +0000https://newscenter.lbl.gov/?p=33821Lawrence Berkeley National Laboratory, in partnership with Sandia National Laboratories/California and Lawrence Livermore National Laboratory, has been awarded $4.15 million by the Department of Energy to jointly launch a new small business voucher pilot.

]]>Lawrence Berkeley National Laboratory (Berkeley Lab), in partnership with Sandia National Laboratories/California (SNL/CA) and Lawrence Livermore National Laboratory (LLNL), has been awarded $4.15 million by the Department of Energy (DOE) to jointly launch a new small business voucher pilot.

“Our pilot, which we’ve named LabSTAR, unites three national labs—Berkeley, Sandia, and Livermore—to serve as a Bay Area ecosystem for providing access to the unique assets of the national lab system, such as basic science, prototyping, analysis, supercomputers, accelerators, and more,” said Alecia Ward, LabSTAR program lead and also head of program and business development for Berkeley Lab’s Energy Technologies Area.

The Molecular Foundry is a U.S. Department of Energy nanoscience center hosted at Lawrence Berkeley National Laboratory and could be used for collaborative research through the Small Business Voucher Pilot.

The funding is part of DOE’s $20 million investment in small business assistance, which is one component of its National Lab Impact Initiative. This initiative seeks to significantly increase the industrial impact of DOE national labs on the U.S. clean energy sector. LabSTAR, with Berkeley Lab serving as the lead, was awarded the pilot for applications in four sectors: battery technologies, fuel cell technologies, geothermal technologies, and advanced manufacturing, which could cover any technology.

“LabSTAR will create opportunities for the national labs to share their unique assets with small businesses, who can leverage our expertise in geothermal technologies, transportation energy, materials science and other fields to create innovative clean energy solutions,” said Carrie Burchard, business development manager at SNL/CA.

Small businesses, defined as a company with fewer than 500 employees, will be able to apply for up to $300,000 in vouchers for work at one of the three national labs. A successful application will require a 20 percent cost share. “They could apply to do research with a particular scientist or use a certain facility, such as the High Performance Computing Innovation Center at Livermore, Sandia’s Combustion Research Facility, or the Molecular Foundry at Berkeley Lab for nanoscale research,” said Ward. “We expect dozens of small businesses will be able to benefit from this program in its first two years.”

“LabSTAR pulls together a consortium of national labs located in the Bay Area that marry cutting-edge science and technology with a regional ecosystem that promotes small business success,” said Rich Rankin, director of LLNL’s Industrial Partnerships Office. “The Lab is excited about the potential this collaboration offers to connect us to the small business community.”

LabSTAR also includes an unprecedented level of support from a diverse range of state, local, and regional partners, as well as startup incubators like Cleantech Open and the Massachusetts Clean Energy Center and business organizations like the Silicon Valley Leadership Group.

“We especially have strong support from incubators in California, Minnesota, Wisconsin, Massachusetts, South Carolina, Georgia, Texas, and Hawaii,” Ward said. “The purpose of these partnerships is to reach as many small and emerging technology businesses as possible and to have as strong an applicant pool as possible.”

Berkeley Lab’s participation in the small business voucher pilot is only the latest of several initiatives undertaken by Lab Director Paul Alivisatos to transform Berkeley Lab into a more market-facing laboratory by connecting basic research with applied sciences. In the last couple years, Berkeley Lab has also launched CalCharge, a public-private partnership for the energy storage industry, and Cyclotron Road, an early-stage energy technology incubation program.

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Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

Founded in 1952, Lawrence Livermore National Laboratory (www.llnl.gov) provides solutions to our nation’s most important national security challenges through innovative science, engineering and technology. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy’s National Nuclear Security Administration.

Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corp., for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies and economic competitiveness.

]]>http://newscenter.lbl.gov/2015/07/09/bay-area-national-laboratories-jointly-launch-new-small-business-voucher-pilot-for-emerging-cleantech-companies/feed/0Berkeley Lab Study Finds that Future Deployment of Distributed Solar Hinges on Electricity Rate Designhttp://newscenter.lbl.gov/2015/07/09/berkeley-lab-study-finds-that-future-deployment-of-distributed-solar-hinges-on-electricity-rate-design/
http://newscenter.lbl.gov/2015/07/09/berkeley-lab-study-finds-that-future-deployment-of-distributed-solar-hinges-on-electricity-rate-design/#respondThu, 09 Jul 2015 14:43:06 +0000https://newscenter.lbl.gov/?p=33795Future distributed solar photovoltaic (PV) deployment levels are highly sensitive to retail electricity rate design, according to a newly released report by researchers from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). The study also explores the feedback effects between retail electricity rates and PV deployment, and suggests that increased solar deployment can lead to changes in PV compensation levels that either accelerate or dampen further deployment.

]]>Berkeley, CA – Future distributed solar photovoltaic (PV) deployment levels are highly sensitive to retail electricity rate design, according to a newly released report by researchers from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). The study also explores the feedback effects between retail electricity rates and PV deployment, and suggests that increased solar deployment can lead to changes in PV compensation levels that either accelerate or dampen further deployment.

“We find that retail rate design can have a dramatic impact on PV deployment levels,” says report author Naïm Darghouth, a researcher in Berkeley Lab’s Energy Technologies Area. “For example, rate design changes currently being considered by a number of utilities, and modeled in our study, can dramatically erode aggregate customer adoption of PV (from -14% to -61%, depending on the design).”

The report, which uses a solar deployment model originally developed at the National Renewable Energy Laboratory, also examines PV deployment levels under broad adoption of time-of-use rates, purely volumetric rates, feed-in tariffs, and avoided cost-based rates. Most of these scenarios lead to deployment levels lower than under a continuation of net metering and current rate designs.

“Our study shows that—at least on a national basis—these two feedback effects largely counteract one another. As such, current discussions that focus largely on the fixed-cost recovery feedback miss an important and opposing feedback mechanism that can in many circumstances moderate the issue of concern,” notes Berkeley Lab’s Ryan Wiser, a co-author on the report.

Exemplifying these feedbacks are the deployment impacts from switching all customers to time-varying rates. In the shorter term, up to about 2030, the study finds that PV deployment is greater than in the reference scenario – a result of the higher average compensation for PV under time-varying rates which boosts PV deployment. However, as regional PV levels increase and the energy and capacity value of PV drops, the compensation for net-metered PV generation under time-varying rates also falls, which leads to lower PV deployment levels. Therefore, proposals to move towards time-varying rates may boost PV deployment in the shorter term, but may actually reduce PV deployment in the longer term.

The report was motivated by the fact that rapid growth of net-metered solar PV has provoked concerns about the financial impacts of that growth on utilities and ratepayers. To address these concerns, an increasing number of states are exploring changes to net metering rules, retail rate structures, or both. According to report co-author Galen Barbose, “Understanding the deployment impacts of potential reforms to rate design and net metering will be critical for regulators and other decision makers as they consider changes to retail rates, given the continued role of PV in advancing energy and environmental policy objectives and customer choice. This report makes a unique contribution by quantitatively assessing these possible deployment impacts.”

The report, Net Metering and Market Feedback Loops: Exploring the Impact of Retail Rate Design on Distributed PV Deployment, may be downloaded at http://emp.lbl.gov/reports/re, along with a factsheet and summary slide deck.

A webinar presentation of key findings from the report will be held today, July 9, at 11 am Pacific Time (2 pm Eastern Time). To receive log-in instructions for the webinar, register at https://goo.gl/uuLVWa.

This research was supported by funding from the U.S. Department of Energy’s SunShot Initiative.

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The SunShot Initiative is a collaborative national effort that aggressively drives innovation to make solar energy fully cost-competitive with traditional energy sources before the end of the decade. Through SunShot, DOE supports efforts by private companies, universities, and national laboratories to drive down the cost of solar electricity to $0.06 per kilowatt-hour. Learn more at energy.gov/sunshot.

Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

]]>http://newscenter.lbl.gov/2015/07/09/berkeley-lab-study-finds-that-future-deployment-of-distributed-solar-hinges-on-electricity-rate-design/feed/0Sensitive and Specific: A New Way of Probing Electrolyte/Electrode Interfaceshttp://newscenter.lbl.gov/2015/07/08/sensitive-and-specific-a-new-way-of-probing-electrolyteelectrode-interfaces/
http://newscenter.lbl.gov/2015/07/08/sensitive-and-specific-a-new-way-of-probing-electrolyteelectrode-interfaces/#respondWed, 08 Jul 2015 23:42:59 +0000https://newscenter.lbl.gov/?p=33820Researchers have developed a new technique that enables sensitive and specific detection of molecules at the electrode/electrolyte interface. This new method uses diffraction from graphene gratings to overcome key difficulties associated with traditional optical spectroscopy that employs infrared probing of buried interfaces.

]]>One of the most important things to understand in battery technology is the precise physical and chemical processes that occur at the electrode/electrolyte interface. However, microscopic understanding of these processes is quite limited due to a lack of suitable probing techniques. Now, researchers at the US Department of Energy’s (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley, have developed a new technique that enables sensitive and specific detection of molecules at the electrode/electrolyte interface.

“Most of the electrical chemical reaction in a battery happens at the electrolyte/electrode interface, and it is important to know how tuning the electrode voltage induces field-dependent chemical processes. This requires distinction between microscopic molecule behavior at the interface, such as physical absorption, and electrochemical reaction from the bulky electrolyte solution,” says Feng Wang, a physicist at Berkeley Lab’s Materials Sciences Division and a member of the Kavli Energy NanoSciences Institute at Berkeley, who led this work. “Our new probing method uses diffraction from grating-like graphene electrodes. We monitor the molecule vibration modes from the diffraction signal in an in-situ, non-invasive and fast technique, taking advantage of both laser technique and graphene properties.”

Wang is an author of a paper describing this research in the journal Nature Communications. Other authors include Ya-Qing Bie, Jason Horng, Zhiwen Shi, Long Ju, Qin Zhou, and Alex Zettl, who is also a physicist at Berkeley Lab and a member of the Kavli Institute.

“The scientific community now has available impressive techniques for the growth, transfer, and geometrical shaping of graphene for electronic and optical application,” says Zettl. Graphene is an attractive choice of electrode for interface studies because it is stable and transparent to infrared light, and is being explored for applications in supercapacitors, batteries, solar cells and displays.

The novel ‘diffraction spectroscopy’ uses polarized infrared radiation incident to an electrode made of graphene systematically cut into a very fine grid or grating. Together with a platinum counter electrode and aqueous electrolyte, this forms an electrochemical cell. Molecular species within the cell attach to the graphene and thereby influence the diffraction characteristics of the grating.

To investigate the molecular species at the electrolyte/graphene interface, the team measured the first-order diffraction from the graphene grating, rather than the transmission or reflection signal as in traditional spectroscopy.

Diffraction signal is generated by periodic variation of optical susceptibility at the interface, which comes from both the graphene grating itself and different adsorbed molecules in the electrolyte double layer induced by the graphene grating. Credit: Feng Wang, Berkeley Lab

“We use the fact that the diffraction signal only probes things that have spatially periodic structures, and design our graphene electrodes to be shaped as a periodic grating. In this case, the molecules of interest are periodically distributed due to the underlying electrode grating, and most of the background signals in the traditional reflection or transmission measurement do not show up,” explains Wang.

This means that any measured diffraction originates from vibrations of adsorbed molecules in the graphene-induced electrical double layer. Relative contrast is enhanced 50 times compared with conventional absorption spectroscopy, and can detect with sub-monolayer sensitivity.

This proof-of-principle study detected CH2 vibrations from surfactant deposition on the graphene electrode as an example, but the technique can be applied to other functional groups at other infrared frequencies.

“Beyond the vibration range of the methyl groups used in this work, there are plenty of other interesting chemical processes involving molecules whose vibration are in the infrared range. The more we know about the interface molecule behavior, the more guidance we have for device design,” concludes Wang.

The research was funded by the National Science Foundation and the Office of Naval Research.

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Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

An image of the USS Independence from the Coda Octopus Echoscope 3D sonar, which was integrated on the Boeing Autonomous Underwater Vehicle (AUV) Echo Ranger. Credit: NOAA and Coda Octopus

About 42 miles southwest of San Francisco and 2,600 feet underwater sits the U.S.S. Independence, a bombed-out relic from World War II. The aircraft carrier was a target ship in atomic weapon tests at Bikini Atoll in the Marshall Islands after the war. Then, in 1951, it was loaded up with 55-gallon drums of low-level radioactive waste and scuttled just south of the Farallon National Wildlife Refuge off the California coast.

Earlier this year, the U.S.S. Independence was rediscovered by a team of researchers led by James Delgado, the director of Maritime Heritage at the National Oceanic and Atmospheric Administration (NOAA). The marine archaeologists used sonar from an autonomous submarine to find the wreckage, but with the ship’s radioactive past, the scientists wondered how safe it would be to actually explore.

During the 2015 mission to survey the ex-USS Independence CVL 22, the Office of National Marine Sanctuaries’ research vessel Fulmar served as the escort boat for Boeing’s Autonomous Underwater Vehicle (AUV) Echo Ranger. The 67-foot aluminum catamaran research vessel’s crew is preparing to tow Echo Ranger to sea.Credit: Robert V. Schwemmer, NOAA

Delgado turned to Berkeley Lab’s Kai Vetter to better understand the radiation hazards. Vetter is the head of applied nuclear physics at Berkeley Lab, nuclear engineering professor at the University of California, Berkeley, and the co-founder of the Institute for Resilient Communities. “They wanted to know if we could ensure the safety of their equipment,” says Vetter, “and to see if you’d pick up contamination if you went down there.”

The short answer, Vetter says, was that neither the submersible nor the team was ever in danger of contamination.

One reason is that water is an excellent radiation shield. Under water, radiation will only extend several inches from contaminated materials, says Vetter. The unmanned research submarine stayed at least 100 feet away from the wreck.

Another reason has to do with the size of the contaminated site with respect to the size of the ocean. While contaminated rust particles from the ship are released and transported by water, the dilution factor of the ocean is enormous, essentially nullifying any radioactive effect.

Relatedly, while a relatively small number of organisms close to the wreck might take up some of these rust particles, the effects of radioactivity are diluted through the food chain because the number of organisms exposed is so small. In contrast, mercury is much more prevalent and widely distributed in the ocean, and this is why its concentration builds up in the food chain.

Aerial view of ex-USS Independence at anchor in San Francisco Bay, California, January 1951. There is visible damage from the atomic bomb tests at Bikini Atoll. Credit: San Francisco Maritime National Historical Park

And finally, says Vetter, it’s important to consider the half-life of the radioactive materials. In this case, the isotopes of concern are cesium 137 and strontium 90, which both have a half-life of about 30 years. This means that after 30 years, half the isotopes responsible for the initial contamination transmute into other non-radioactive isotopes. It’s been over 60 years since the U.S.S Independence was scuttled, which means that less than a quarter of the initial radioactive isotopes remain.

The shipwreck site of the former aircraft carrier, Independence, is located in the northern region of Monterey Bay National Marine Sanctuary. Half Moon Bay, California was the port of operations for the Independence survey mission. The first multibeam sonar survey of the Independence site was conducted by the NOAA ship Okeanos Explorer in 2009.Credit: NOAA’s Office of Ocean Exploration and Research and NOAA’s Office of National Marine Sanctuaries

Still, to demonstrate with data, Vetter brought a team of researchers and students to the harbor in Half Moon Bay, CA to test the submersible after it had captured sonar images of the aircraft carrier. Armed with instruments called dosimeters that pick up ionizing radiation, the researchers found no evidence of contamination on the submersible. It wasn’t a surprise, says Vetter, since the craft never got close enough to the ship and even if it had, the contamination would have diluted away as it was tugged back to shore.

The NOAA expedition collected its sonar images from a distance, but Vetter hopes to someday work with a submersible that gets an up-close view of the ship, the 55-gallon barrels, and the radioactivity. Such a project would require a specially designed detector to read the radiation on site, Vetter explains. “It would be exciting to build a dedicated system with some advanced technologies to figure out what is sitting down there in that old vessel,” he says.

For more information about the Institute for Resilient Communities go here.

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Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit http://www.lbl.gov.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.